Cooling device



J. KUBLER COOLING DEVI GE June 24, 1930.

Filed Jan. 2, 1929 Patented June 24, 1930 UNITE STATES FATE? OFFICE JOHANNES KUBLER, 0F BADEN, SW'ITZERLALTD, ASSEGNGR '20 .AKTIENG-ESELLSGI-IAFT BROWN BOVERI & CIR, 0F BADEN, SVJITZEBLAND, A JOINT-STOCK COMPANY OF SWITZERLAND Application filed January 2, 1929, Serial No. 3238,912 and in Germany January 2, 1928.

This invention relates to improvements in means for cooling the fluid filling casings or tanks inclosing various types of electric equipment and is particularly applicable to the cooling of oil-immersed transformers.

The tanks or casings in which electric equipment such as transformers are commonly housed are usually fill d wi h an sulating fluid such as oil and are oroviocd with means for exposing the oil to air cooling, exteriorly of the tank, by the use of circulating device acting as a radiator, for obtaining such air cooling. Various devices have been proposed for permitting tl e circulation of air through and about the heat radiating surfaces but such devices, heretofore, involved the handling of large quantities of air and have not been eiiicient in producing uniform cooling in all of the radiating devices nor in all parts of the same radiating device.

The present invention provides m ans for circulating cooling air about the radiators, attached to a fluid filled tank con ining electrical equipment, in such manner that the amount of air necessary to secure cooling of the same is decreased and for uniformly cooling the several radiators.

It is, therefore, among the objects of the present invention to provide cooling means for equipment of the character above described in which the cooling effect will be increased and will be equalized over the entire radiating surfaces without requiring increase in the area of heat transfer surface or in the amount of air circulating thereabout.

Another object of the invention is to provide means for obtaining a forced circulation of air particularly in the upper portions of the radiating devices without increasing the amount or the pressure of the air supplied thereto.

A further object of the invention is to provide a radiating device of such structure that the air supplied thereto under pressure will be uniformly distributed throughout the entire device and will tend to in crease the amount of air drawn into and through the device without requiring an increase in the supply of air.

Other objects and advantages of the pres ent invention .vill appear hereinafter in the description and the accompanying drawings in which Figure l is a longitudinal section taken on the line A-B of Fig. 2, and

2 is a section taken on the line CD of Fig. 1, and

Fig. 3 is a crosssection taken on the line EF of Fig. 2.

Referring more specifically to the drawings, the cooling device or radiator coinprises an upper header 5 and a lower header 6 connected by a plurality of tubes 7 which are arranged in horizontally staggored relation and at an angle to the vertical line through the center of the headers. Each of the headers is adapted to be connected to a fluid filled tank enclosing an electrical device (not shown), for which cooling of the fluid is desirable. inclining the tube 7 at an angle to the vertical so spaces the tubes that a dot-inwardly divergin central passageway is formed which e);-

tends from the upper header 5 to the lower header 6.

A plurality of-nozzles S, 9 and 10, arranged in a substantially vertical direction, extend through the lower header 6 and into the central passageway formed by the tubes 7 The nozzles are connected with and adapted to receive air under pressure from a casing or conduit 11 arranged to be supplied with air under pressure from a blower or other source of compressed air (not shown).

The nozzles 8, 9 and 10 discharge into the central passageway formed by the tubes 7 at different levels or heights from the lower header so that air arising from the nozzles, being heated by contact with the heat radiating tubes 7, expands, thereby forming a partial vacuum within the tube 5 structure which causes cool. air circulating about the radiating structure to flow thereinto to augment the cooling air discharged from the nozzles. By this means the mass of air flowing over the radiating surface of of the air under pressure supplied thereto is facilitated.

A thcrmo-siphon circulation of fluid takes place through the radiator because the heated oil or other fluid rises to the top of the tank enclosing the electrical device and enters the top header. Being in contact with the air cooled walls of the header, the oil is slightly cooled and, becoming denser, flows downwardly through the tubes. As

the oil in the tubes is divided into smaller masses in contact with the cooled walls of the tubes, cooling of the oil is facilitated and the temperature of the oil entering the low as header and returning to the tank is reduced to approximately atmospheric temperature.

It will be apparent that distribution and circulation of the air in the manner provided for by the invention produces a more effective use of the radiating devices thereby causing a more rapid circulation or the oil than was possible heretofore which increases the efliciency of the entire device beyond that of the structures heretofore known. 85 The radiation tubes may be arranged in any suitable manner to provide a hollow space therein and may be suitably formed in a flattened or oval shape or provided with other means to facilitate cooling of the fluid circulating therein by increasing area of the heat transfer surfaces thereof.

Although but one embodiment has been illustrated and described, it will be understood that various other embodimcnts are possible, and that various changes may be made without departing from the spirit of the invention or the scope of the claims.

The invention claimed is:

1. In a cooling device for inclosed electrical apparatus immersed in an insulating fluid, headers adapted to communicate with the inclosure for said apparatus, a plurality of tubes connecting said headers and arranged to form a downwardly divergent passageway central therethrough, a plurality of nozzles discharging at diii'erent points within the passageway, and means for conducting air under pressure to said nozzles.

2. In a cooling device for inclosed elee trical apparatus immersed in an insulating fluid, an upper and a lower header adapted to communicate with the enclosure for said apparatus, a plurality of tubes arranged at an angle to a vertical line through said 68 headers and connected therewith t form a the tubes is increased and cooling by means 

